Apparatus for controlling hydraulic pumps.



M. c. smsa. APPARATUS FOR CONTROLLING HYDRAUILIC PUMPS.

APPLICATION FILED MAY I9. 19M- Pmem edi 11m. 4,1917. 2 SHEETS-SHEET I.

WITNESSES M; C. STEESE. APPARATUS FOR CONTROLLING HYDRAUHC PUMPS.

AFPLICATLON FILED WW 9'. I914. n

Patented Dec. 4L, 191 f.

2 SHEETS-SHEET 2- MARCUS C. STEESE, OF YOUNGSTOWN, OHIO.

APPARATUS FOR CONTROLLING HYDRAULIC PUMPS.

Specification of Letters Patent.

Patented Dec. 4, ram.

Application filed May 19, 1914. Serial No. 839,550.

To all whom it may concern:

Be it known that I, MARCUS C. S'rnnsn, a resident of Youngstown, in thecounty of Mahoning and State of Ohio,have invented a new and usefulImprovement in Apparatus for Controlling Hydraulic Pumps, of which thefollowing is a specification.

This invention relates to apparatus for controlling hydraulic pumps andparticularly duplex pumps. The object of the invention is to providecontrolling apparatus which regulates the pump speed in exact accordancewith variations in the demands upon it, which prevents racing of thepump and the sudden admission to the engine operating the same of alarge supply of fluid pressure and thereby avoids liability of breakageor of overstraining the pump parts, and which is so arranged as toprovide a reservoir of liquid, so that an increase in the demand uponthe pump is supplied immediately, while the pump speeds up to take careof the demand.

The invention comprises the construction and arrangement of partshereinafter described and claimed.

In the drawings, which represent one embodiment of the invention, Figure1 is a view partly in side elevation andpartly in section of anembodiment of my invention, the position shown being that when-the pumpis running at a speed intermediate its minimum and maximum speeds; Fig.2 is an end elevation; Figs. 3 and I are detail views of certainconnecting rods; Fig. 5 is a detail view showing a modification; Fig. 6is a detail view showing a modified form of some of the parts; and Fig.7 is a detail cross section on the line 77, Fig. 1.

Hydraulic pumps are commonlyv controlled by means of a balanced valveplaced in the conduit which supplies fluid pressure, such as steam, air,or other substance under pressure, to the driving cylinders of the pump,this valve being operated by an accumulator which is connected to themain fluid line from the pump to the mill. The travel of thisaccumulator controls the amount of fluid pressure admitted to thedriving cylinders of the pump and thus controls its speed and the amountof fluid forced by the pump to the millf Several types of apparatus havebeen used for controlling this valve. In one arrangement the accumulatoroperates two trips which are connected to the valve. In a secondarrangement the accumulator is Experience has shown that the effectproduced by the arrangements described upon the engine which operatesthe pump is detrimental to its action because fluid pressure is notsupplied in direct proportion to the variation of the demands on thepump, and the engine and pump are therefore submitted to heavy and unduestrains and stresses which are liable to result in breakage or at leastin weakening the parts. If the pump is of the compound or tripleexpansion type or any type in which the driving pressure is not the samein all cylinders, it frequently happens that the pressure in allcylinders other than the high pressure cylinders becomes wholly depletedif the pump stands at rest for any appreciable length of time. Then,when an outlet from the main fluid line from the pump to the mill isopened up and a demand. thereby made upon the pump for fluid, theaccumulator moves to supply this demand. In the first arrangementdescribed the controlling valve is not opened until the accumulatorreaches nearly the end of its stroke and then it opens suddenly topractically its full extent. In the second arrangement the valve isopened uniformly in direct proportion to the movement of the accumulatorshell and tends to start the pump. This quick or uniform opening of thevalve throws a large volume of fluid pressure into the high pressurecylinders and tends to start the pump at practically its maximum speedfrom rest or from a very low speed. After the pump has made one or twostrokes, all cylinders are filled up and site direction from its formertravel, its

barrel is again filled up to its maximum reservoir capacity and thefluid supply valve is closed, either suddenly with the trip arrangementdescribed, or uniformly with the accumulator motion in the secondarrangement described. The pump is quickly stopped, thereby producingthe same rack and strain'of the parts as before, but in the reversedirection.

l/Vith this action, therefore, unless the mill or mills which are beingsupplied by the pump are continually calling for a large percentage oithepump capacity the entire action of the control mechanism is to startand stop the pump under full load conditions and the pump is therebystrained 1 leakage only, the fluid is supplied to the engine at first ata very low rate, which gives the engine ample opportunity to fill all ofits cylinders with the proper amountsof driving fluid and .to pick upspeed gradually, and, as the controlling valve is further openedv up, a,gradually lncreasing amount ofdriving fluid is supplied to all .ofthecylinders, to thereby speed the pump up. until it can fully take care ofthe entire demand. With this arrangement there is no liability of theengine racing when there is an extra heavy demand imposed upon any onecylinder or upon-the whole pump unit before it hasreached the properworking conditions to take care of the extra duty.

Also, for either small or great variations in the demand, thecontrolling apparatus reguzlates the fluid pressuresupply valve so thatit does not open orclosein direct proportion to the demand variation,but to secure a variation in the speed of operation of the engine and.pump and in the output of the pump which is directly proportional tothe demand variation.

In the arrangement shown in the drawings, the accumulator tank is ofcommon construction and comprises a suitable vessel one. which may beloaded with water and is provided with an inner closed cylinder 2slidable upon the upper end of a conduit 3 which is provided with aconnection 3? to the main line supplied by the pump. It willbe-vunderstood that when the pump is running or when the operating fluidpressure supply is turned into the pump and it is at rest, the headproduced forces liquid up through the conduit 3 into the cylinder 2 andlifts the accumulator to a level depending upon the demand upon thepump. The conduit and tank are mounted on a suitable base i provided atone side with b 'ackels 5 in which is journaled a shaft (Shaving adouble armed lever rigidly connected therewith. One arm of said levercomprises one or a pl rality of horizontal members 7 carryingcounterweights 8 adjustable thereon, while the other arm of the lever isa member f) riveted or otherwise secured to a yoke 10 on the shaft (5and which arm extends up along the side of the accumulator tank. The arm9 is shown an an I-beam Whose main body portion is straight and inclinedslightly away from the accumulator tank and whose upper end is inclinedmore sharply away from said tank, the two inclined portions of said armbeing joined at the bend 11. Said arm coiiperates with the accumulatortank and is oscillated about the pivot 6 as the tank rises and falls bya grooved roller 12 on the tank, against which the lever is held by thecounterweights 8. Arm 9 is inclined away from the tank so that asthetank drops it forces the lever to turn on its pivot and swing fartheraway from the tank. Instead of the arrangement just described, the tankmay be provided with apin 13 traveling up and down in a longitudinalslot 1% in the arm 9, as in Fig. 6, and thereby moving it positively inboth directions, in which case the counterweights may be dispensed with.Either arrangement described prevent rotation of the tank on itsvertical axi and does away with the necessity of special tank guides.

15 represents the casing of the valve for controlling the liuid pressuresupply to the engine for operating the pump. Said valve may be of anysuitable type and is shown as a balanced valve member 16 cooperatingwith two valve seats 17 and having a stem 18 extending to the outside ofthe valve casing and connected to a lever arm 19 provided with theadjustable counterweight 20 and pivoted to a fixed part of the casing.

Arm 9 and lever 19 are connected by suitable mechanism arranged toproduce a variable movement of the valve for uniformvariations inmovement of the accumulator tank in the manner before described. The

connections shown comprise a double armed lever pivotally mounted in abracket 26 depending from the casing 15 of the valve.

One arm of said lever, such as the arm 25, is connected to the verticalarm 9-, such as by the rigid link. 27 preferably provided lever is inthe form of a large segment connected to the lever 19 by a rigid link 32which may be provided with a turnbuckle for adjusting its length in thesame manner as the link 27 and is shown as comprising two memberstelescopically connected as at 32 and fastened together by a cross pin33 which may be placed in the proper ones of anumber of apertures insaid members. The pivot pin 40 connecting the lever arm 31 and link 32may also be placed in any one of a number of apertures 41 and 4E1 insaid lever arm and link 32 inv order to adjust the link with referenceto the lever arm as will be readily understood.

The apparatus described operates as follows Tn Fig. 1 of the drawingsthe parts are shown with the accumulator tank in a position intermediateits two extremes of movement, that is, in a position in which somedemand is being made on'the line and the pump is supplying saiddemand.The ac cumulator tank stands in a position with its roller at the pointA and at a level depending upon the head and the demand on the line. Arm9 is held in contact with the roller 12 and the valve 16 is partlyopened and supplies the proper amount of fluid pressure to the engine tocause the pump to just keep pace withthe demand upon it. If the demandupon the main line is reduced the pressure therein increases and liquidflows up into the accumulator tank through 3 and elevates the same to aposition in which the roller is at approximately the point marked B,that is, just a little below the bend 11 in arm 9. If an abnormal demandis made upon the line such as by a break therein, the accumulator tankdrops to a position in which the roller stands at the position marked C,with the accumulator tank close to the bumpers 45.

Let us assume a condition in which the roller 12 occupies the positionindicated at B, in which the pump is barely moving, and only suppliesthe leakage from the main line, all outlets from which are closed. Whenan outlet from the main line is opened the first action is for theaccumulator tank to drop, thereby causing the roller to move down alongthe inclined arm 9, and swing the same away from the accumulator tank.In its upper position the roller is at a con siderable distance from thepivot 6 so that a given amount of downward movement of the rollerproduces a comparatively small movement of the arm 9. As the tank movesdownwardly however, the roller approaches closer to the pivot 6 and thesame given uniform movement of the tank produces a greater effect uponthe lever arm as it approaches said pivot.

The movement to the left of arm 9 is communicateddirectly to the leverarm 25 by 25, practically the entire motion of the arm 9 in a horizontaldirection is transmitted to the lever arm 25, which produces acorresponding movement of the pivot 40 connecting the lever arm 31 andlink 32 in the con trary direction or to the right in Fig. 1. The pivot4:0 also travels in a circular path, so that its motion has twocomponents, a horizontal component and a vertical component, of whichonly the vertical component is transmitted by the link 32 to the lever19 which operates the valve. WVhen the pivot 40 is in its lowestposition a given amount of movement to the right has only a smallvertical component but as said pivot moves farther and farther to theright the vertical component increases and the horizontal componentdecreases, so that the efl'ect upon the valve produced by uniformmovement of the pivot 40 increases as the valve opens.

The increasing effect of the accumulator movement on the fluid pressurevalve is due to the fact that it is not the value of the angularmovement of the parts which is transmitted to said valve, but only thevalue of the sine of the angular movement. This peculiar effect isproduced by two different parts of the mechanism, first by the arm 9 andsecondly by the pivot 40 at the end of the lever arm 31. The net resultis that when a demand is made upon the pump by opening an outlet fromthe line, the valve at first is opened very slowly and supplies fluidpressure to the engine side of the pump at a slow rate which enables itto start gradually without sudden impulse and without shock and rackingmovement, and which allows the cylinders of the engine tofill up withfluid pressure before the full supply is turned on. In the meantime theaccumulator tank itself has been supplying the demand upon the line andas it drops lower and lower gradually produces an increased openingefl'ect upon the valve and admits an increasing supply of fluid pressureto the engine. By the time the valve is opened sufliciently to admit afull supply of fluid pressure the engine cylinders have filled up andthe pump is running at a fair speed, so that it picks up to full speedwithout straining its parts. In practice the controlling apparatus isvery sensitive and adjusts the fluid supply so that the engine speedgradually increases to a point where the pump fully supplies the demandupon it, at which point the accumulator tank becomes stationary, as at apoint where the rolleris at the position marked A in the drawings.

If new the demand on the pump is reduced as by closing one or more ofthe outlets from the line, the first effect is for the liquid to rush upinto the barrel of the accumulator tank and lift said tank, causing theroller 12 to travel up along the arm 9.

Arm9 is held in contact with said roller by the counterweight 8 andtherefore moves to the right in Fig. 1, oscillating the lever 25-31 andmoving the valve in the closing duced by a given upward movement of thetank is comparatively great, the valve movement, for a given upwardmovement of the tank, gradually decreasing as the tank moves upwardly.

In operation, the accumulator tank rises and falls as the demand uponthe pump decreases or increases, but the varying. effect produced on thevalve by uniform move ment of the accumulator tank is such that theregulating apparatus does not hunt, but has a very steady movement whichat times is almost imperceptible although it takes place constantly.

If all the outlets from the main line are closed the accumulator tankshould rise to the position in which the valve is fully closed, whichposition is the one when the roller is at the point marked B, that is,just below the bend 11 in the arm 9. If the valve is choked with a smallparticle of dirt or foreign matter so that it does not fully close thepump keeps on operating and forces the liquid up. into'the accumulatortank which rises to an abnormally. high position, that is, above thebend 11. The upper sharply inclined end portion of the arm 9- thenpermits said arm to be moved over forcibly and sharply to the right inFig. 1 by the counter-weight 8, which is usually effective to fullyclose the valve under all circumstances commonly encountered inpractice. This arrangement stops the pump under unusual conditions andprevents it from lifting the accumulator tank to an unsafe position.

Fig. 5 shows a modification in which the arm 9 is so arranged as toclose the valve in case the accumulator tank falls materially below itsdownward limit of movement. In

lowest limit of travel or to a position in which theroller 12 isopposite the bend 42,

whereupon the arm 9 is forced fully over to the right in Fig. 5 by thecoLmt'er-weight 8, so that the roller 12 enters the bend 42. Thisentirely closes the fluid pressure supply valve and stops theengine,thereby preprising venting the engine and pump from racing and possiblydestroying or injuring themselves. Arm 9 may if desired be provided witha movable or removable cover member 43, shown in dotted lines, which canbe placed over the bend 42 to cut out this safety feature.

The apparatus described is simple and forms a perfect regulating devicefor fluid pressure pumps. It controls the pump in such manner that ittakes care of all variations in load imposed thereupon, and suppliesfluid pressure to the engine for operating the pump in quantities whichare so regulated as to change the pump speed in direct proportion to thevariation in demand. At the same time the apparatus is so arranged as toavoid hunting, such as occurs in most governors, and thereby isverysteady and even in operation.

What I claim is:

1. Apparatus for controlling the motive fluid for operating hydraulicpumps, commeans responsive to variations in the pressure produced by thepump, a valve for controlling the motive fluid for operating said pump,and mechanism operated by the pressure responsive means for actuatingthe valve, said mechanism being arranged so that the rate of movement ofthe valve varies in uniformity relative to the rate of movement of thepressure responsive means.

2. Apparatus for controlling the motive fluid for operating hydraulicpumps, comprising meansresponsive to variations in the pressure producedby the pump, a valve for controlling the motive fluid for operating saidpump, and mechanism operated by the pressure responsive means foractuating the Valve, said mechanism being arranged so that when thepressure responsive means moves under variations in pressure the valveis actuated at a varying rate.

3. Apparatus for controlling the motive fluid for operating hydraulicpumps, comprising means responsive to variations in the pressureproduced by the pump, a valve for controlling the motive fluid foroperating said pump, and mechanism operated by the pressure responsivemeans for actuating the valve, said mechanism being arranged so thatwhen the pressure responsive device moves uniformly in one direction dueto decrease in pressure the valve is first actuated slowly and then morerapidly.

4. A pump governor comprising means responsive to the pressure producedby the pump, a valve for controlling the motive fluid for operating thepump, and mechanism actuated by the pressure responsive means foroperating the valve, said mechanism being arranged so that the valve isactuated at a varying rate of speed relative to the rate of speed of thepressure responsive sive means for operating the valve, said mechanismbeing arranged so that as the pressure responsive means moves at auniform rate in response to decreases in pres-.

sure the valve is first opened slowly and then more rapidly, saidmechanism being also arranged so that when the pressure responsive meansis moved to the limits of its travel by abnormal increases or decreasesin pressure the valve is automatically closed.

6. A pump governor, comprising means responsive to the pressure producedby the pump, a valve for controlling the motive fluid for actuating thepump, and mechanism actuated by the pressure responsive means foroperating the valve, said mechanism being arranged so that as thepressure responsive means moves in response to decreases in pressure thevalve is first opened slowly and then more rapidly and as the pressureresponsive means moves under increases of pressure the valve is firstclosed rapidly and then more slowly.

7. A pump governor, comprising an accumulator responsive to the pressureproduced by the pump, a valve for controlling the motive fluid foractuating the pump, a pivoted cam bar normally biased into engagementwith a camming surface on the accumulator, and a series of leversconnecting the cam bar and the valve arranged so that as the accumulatormoves uniformly the valve is actuated at a varying rate.

8. A pump governor, comprising an accumulator responsive to the pressureproduced by the pump, a valve for controlling the motive fluid foractuating the pump, a pivoted cam bar normally biased into engagementwith a camming surface on the accumulator, and a series of leversconnecting the cam bar and the valve arranged so that as the accumulatormoves uniformly in response to decreases in pressure the valve is firstactuated slowly and then more rapidly.

9. A pump governor, comprising an accumulator responsive to variationsin the pressure produced by the pump, a valve for controlling the motivefluid for actuating the pump, a pivoted cam bar normally biased intoengagement with the cam surface on the accumulator, and a series oflevers connecting the cam bar with the valve whereby movements vof theaccumulator are transmitted to the valve, said cam bar being shaped sothat when the accumulator reaches the limits of its movement in eitherdirection due to abnormal increases or decreases in pressure the box, isautomatically operated to close the valve.

10. Apparatus for controlling the fluid supply for operating hydraulicpumps, comprising an accumulator tank supplied by the pump and arrangedto rise and fall with variations in demand upon the pump, a valve in thefluid supply for operating the pump, a lever having an inclined portionand arranged to be controlled by said ac cumulator tank, a pivoteddouble armed lever, and connections between said levers and between saiddouble armed lever and valve for controlling the latter.

11. Apparatus for controlling the fluid supply for operating hydraulicpumps, comprising an accumulator tank supplied by the pump and arrangedto rise and fall with variations in the fluid supply for operating thepump, a vertical pivoted lever at one side of said tank and arranged tomove about its pivot in accordance with the rise and fall of saidtank, apivoted lever operated by said vertical lever, and connections betweensaid second named lever and valve for operating the latter.

In testimony whereof, I have hereunto set my hand.

MARCUS G. STEESE.

Witnesses ELBERT L. HYDE, WmLmM B. WHARTON.

topics or this patent may be obtained for five cents each, by addressingthe Gommissioner or Watenta. Washington, W. e.

